PROJECT SUMMARY This application will provide the Principal Investigator, Dr. Alvaro Alonso, with protected time and other support to (1) accelerate a successful record of mentoring junior clinical investigators and graduate students engaged in patient-oriented cardiovascular research; (2) obtain additional training in omics, machine learning, and mentoring best-practices; and (3) advance Dr. Alonso's ongoing research on the risk factors and mechanisms contributing to the development of atrial fibrillation (AF). Mentoring activities will build upon the ongoing involvement of Dr. Alonso in several training programs at Emory University, including an NHLBI-funded multidisciplinary T32 training grant on cardiovascular health disparities, the research-track Cardiology fellowship program at the School of Medicine, and the Master of Public Health and PhD programs in epidemiology at the Rollins School of Public Health. Training will focus on cutting-edge methodological areas in rapid development, including integration of omic technologies and machine learning in patient-oriented research, as well as acquisition of skills in academic, research, and clinical mentoring. Finally, this award will support a research project that extends Dr. Alonso's ongoing work on understanding the factors influencing the development of the AF substrate, understanding AF pathophysiology, and preventing AF-related outcomes. The specific aims of this research are: (1) to identify novel AF phenotypes (phenogroups) using extensive clinical and multi-omic data (?phenomapping?), (2) to discover specific risk factors for the different AF phenogroups, and (3) to determine associations of AF phenogroups with selected endpoints (stroke, heart failure, mortality). These research aims will be carried out in the context of the Emory Cardiovascular Biobank, an ongoing prospective registry of patients undergoing cardiac catheterization in three Emory-affiliated hospitals currently including approximately 7,000 unique individuals with detailed phenotyping, clinical outcomes, and multi-omic markers. In summary, the activities proposed in this application will favorably impact Dr. Alonso's capabilities to conduct cutting-edge and innovative patient-oriented research on cardiovascular prevention and his ability to perform as a highly qualified mentor for junior clinicians pursuing research on clinical cardiovascular epidemiology and prevention.